钢管套箍混凝土桥墩拟静力试验研究

Pseudo-static testing of concrete piers with steel tube hoops

设计制作3根钢管套箍混凝土桥墩试件,对其开展拟静力试验,获得钢管套箍混凝土桥墩的损伤过程与破坏机理,分析延性、等效黏滞阻尼系数、刚度退化、强度衰减及残余位移等抗震性能的影响规律.结果表明,采用钢管剪力键与灌浆套筒组合连接的钢管套箍混凝土桥墩的各项抗震性能指标均达到了钢管套箍整体式混凝土桥墩的抗震性能指标,比仅由钢管剪力键连接的钢管套箍混凝土桥墩滞回曲线更为饱满,水平峰值荷载和位移延性系数分别提高12.93%、27.17%,等效黏滞阻尼系数大、自复位能力强、残余位移小,是较理想的预制桥墩型式.采用ABAQUS程序建立有限元计算模型,进行拓展参数分析,发现轴压比、长细比、套箍系数和钢管剪力键嵌入深度与墩身高度比是影响钢管套箍混凝土桥墩抗震性能的重要参数.

Three steel tube hoop concrete pier specimens were designed and fabricated,on which a pseudo-static test was carried out and the damage process and failure of the steel tube hoop concrete piers were obtained.The influence of ductility,equivalent viscous damping coefficient,stiffness degradation,strength attenuation and residual displacement on seismic performance were analyzed.The test results showed that the seismic performance of steel tube hoop concrete pier with a steel tube shear connector and grouted sleeves were all up to the seismic performance index of a steel tube hoop integral concrete pier.Compared with the steel tube hoop concrete pier connected only by a steel tube shear connector,the one connected by a steel tube shear connector and grouted sleeves was fuller,the horizontal peak load and displacement ductility coefficients were increased by 12.93%and 27.17%respectively,the equivalent viscous damping coefficient was large,the self-reset ability strong,the residual displacement small,thus constituting an ideal prefabricated bridge pier type.The finite element calculation model was established by the ABAQUS program,and the extended parameter analysis was carried out.Studies have shown that the axial compression ratio,slenderness ratio,confinement coefficient,embedded depth of steel tube shear connector and pier bridge height ratio are important parameters affecting the seismic performance of steel tube hoop concrete pier.